1. Field of the Invention
This invention relates to a method that can provide corrections of distortions of an imaging device.
2. Introduction to the Invention
It is well known to employ an imaging device, for example, a lens, a diffraction grating, or a mirror, as an important component of an optical system, for example, a telescope. To this end, it is desirable that the surface accuracy of the imaging device realize an optimal optical quality. For example, it is desirable that the optical quality of the imaging device not be unduly compromised by imaging device shape distortions due to, e.g., thermal distortions, material inhomogeneities, stress relaxation, or errors in support forces.
One method of compensation for this possible fall off in optical quality is to apply forces to the imaging device, thus introducing deformations that cancel out the accumulated errors. This method is referred to as active optics. For instruction on active optics, reference may be made for example to R. N. Wilson, F. Franza and L. Noethe, "Active optics I: a system for optimizing the optical quality and reducing the costs of large telescopes", J. Modern Opt. 34(4) 485-509 (1987); J. H. Hardy, "Active optics--don't build a telescope without it!" in International Conference on Advanced Technology Optical Telescopes, G. Burbidge and L. D. Barr, eds., Proc. SPIE 332, 252-259 (1982); and F. B. Ray and T.-Y. Chunt, "Surface analysis of an actively controlled telescope primary mirror under static loads, "Appl. Opt." 24(4), 564-569 (1985). The disclosures of each of these references is incorporated by reference herein.